// Copyright 2015 The Go Authors. All rights reserved.// Use of this source code is governed by a BSD-style// license that can be found in the LICENSE file.// Go execution tracer.// The tracer captures a wide range of execution events like goroutine// creation/blocking/unblocking, syscall enter/exit/block, GC-related events,// changes of heap size, processor start/stop, etc and writes them to an io.Writer// in a compact form. A precise nanosecond-precision timestamp and a stack// trace is captured for most events. A trace can be analyzed later with// 'go tool trace' command.package trace
import (
"io"
"runtime"
)
// Start enables tracing for the current program.// While tracing, the trace will be buffered and written to w.// Start returns an error if tracing is already enabled.func Start(w io.Writer) error {
if err := runtime.StartTrace(); err != nil {
return err
}
go func() {
for {
data := runtime.ReadTrace()
if data == nil {
break
}
w.Write(data)
}
}()
return nil
}
// Stop stops the current tracing, if any.// Stop only returns after all the writes for the trace have completed.func Stop() {
runtime.StopTrace()
}